Rotate Plot Image breaks texture size

**Describe the bug**
When used Rotate Plot Image that breaks texture size.

[2024-03-01 14-35-15.webm](https://github.com/emilk/egui/assets/6862092/f7191283-c586-4644-8e36-a3ef145072bc)

**To Reproduce**
Steps to reproduce the behavior: https://github.com/nrot/EguiPlotImageBug

**Expected behavior**
Like without rotating, image saved his aspect.

**Desktop (please complete the following information):**
- OS: Linux, Windows
- Browser: Not checking
- Version 0.26.2

**Additional context**
I think it is bug with rotated texure. But i can`t figure out why it is breaks size. [May be this](https://github.com/nrot/egui/blob/82179d5eecc02c00e578244e4e0e98da80f51915/crates/epaint/src/mesh.rs#L291)